Detect EE binary difference
We failed to detect EE only binary changes: https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/12229#note_171670132
It can be difficult to extend
ee-specific-lines-check to support this, but we can add
ee-binary-diff-check to check this kind of differences, by pointing out any difference between CE/EE for binary files. We don't allow any binary difference, regardless any changes. In contrast,
ee-specific-lines-check does allow "current" difference.
It doesn't seem that Git can easily list all binary files though. We might need to find a way to get a list of files, and compare them with CE and EE. We might want to do this via checksum or so if
git diff doesn't work for this.